When I upload a new version, with the mwEmbed gadget enabled, I always get a warning, because the file currently exists. There is no feedback on why this error is occurring, but it is because you are overwriting the earlier file of course.

This is a question of functionality that is reduced by the usage of this gadget, because normally, you do get such visual feedback and explanation. I looked into it, and found that the submit actually triggers an API call with jsonfm, apparently on purpose, so providing such visual feedback is not possible atm.

It seems that the action of the form is remapped to an API destination. instead of using an XHR command and that jsonfm is used to prevent IE from downloading the response. This is probably not a good idea for Commons "upload new version" uploads to Commons.

Version: unspecified
Severity: major